Method and device for providing electric lamp bulbs with an inner layer of very small light diffusing particles



Dec. 28, 1954 J. G. KRONOUER 2,698,257 METHOD AND DEVICE FOR PROVIDING ELECTRIC LAMP BULBS WITH AN INNER LAYER OF VERY SMALL LIGHT DIFFUSING PARTICLES Filed Feb. 10, 1951 In ven' lmr Johan Geoccg e Kronouer,

AGENT United States Patent METHOD AND DEVICE FOR PROVIDING ELEC- TRIC LAMP BULBS WITH AN INNER LAYER 0F VERY SMALL LIGHT DIFFUSING PARTICLES Johan George Kronouer, Eindhoven, Netherlands, as-

signor to Hartford National Bank and Trust Company, Hartford, Conn., as trustee; patent dedicated to the Public insofar as it relates to lamps and lamp parts to the extent stated in document recorded in the United States Patent Office April 13, 1954 Application February 10, 1951, Serial No. 210,300 Claims priority, application Netherlands March 15, 1950 Claims. (Cl. 117-18) This invention relates to a method of and a device for providing electric lamp bulbs with an inner layer of very small light-diffusing particles.

It is known to provide such a layer of very small particles, which in most cases consist of silicon dioxide, by arranging a bulb above a device producing smoke of such particles. This device is usually a burner and will hereinafter therefore be indicated as a burner. A smokeproducing substance and a combustion means, for example ethyl silicate and oxygen, are burnt in this burner. It is common practice to give the bulb a rotational movement so that as it were a plurality of thin layers are provided on one another and any irregularities of one layer are neutralised by the other. The evenness of the layer of deposited particles is thus enhanced. This evenness of the layer has to satisfy very severe requirements, since irregularities are highly detrimental to the appearance of bulbs. It has been common practice in coating a large number of bulbs to use a plurality of such burners and to treat one bulb above each burner.

It has been found that, even when the said burners per se operate in the manner desired and each bulb acquires a regular coating, differences between the bulbs still occur since the production of smoke is not the same for all the burners.

The object of the invention is inter alia to obviate this disadvantage.

According to the invention, use is made of a series of devices (burners) for producing smoke, over which a series of bulbs are led in a step-wise manner such that the layer formed in each bulb is built up by a plurality of devices.

Irregularities of one burner thus do not become manifest in the final product. It is not necessary to keep all burners operative simultaneously, and more particularly in the case of a large series of burners it is possible to put one or more out of use for cleaning or repairs.

The device according to the invention is constituted by a series of devices (burners) for producing smoke and a transport device for displacing the bulbs, which transport device is adapted to move the bulbs in a step-wise manner over the burners.

In order that the invention may be readily carried into etiect, an example will now be described in detail with reference to the accompanying drawing.

In the accompanying drawing, the reference numeral 1 indicates a number of burners for producing a smoke of small particles. An organic silicon compound, for example ethyl silicate, which oxygen is burnt in the burners. The construction of such burners is known per se. The burners are in this case supplied through two conduits 2 and 3.

Above the burners 1, which are arranged in a row, is a table 4 having a series of apertures 5, there being an aperture above each burner.

Necks 6 of bulbs 7 are introduced into the apertures 5. The bulbs 7 bear on the edges of the apertures 5, the necks 6 being slipped on the burners 1.

Arranged above the bulbs is a transport device which is shown diagrammatically by a straight tube 8 having a number of branches 9 each of which carries a suction member 10,

The transport device is moved on by a driving mechanism (not shown). The movement of an arbitrary part of the transport device is shown diagrammatically in Fig. 2 on a larger scale than in Fig. 1.

Point P shows the position which the device occupies in the position shown in Fig. 1. The tube 8 is evacuated, with the result that the suction members take hold of the bulbs. Subsequently, the device moves upwards to point Q so that the necks 6 are lifted till above the table 4. Subsequently, the device moves to the right to point R and then downwards to point S, which lies slightly higher than point P. Here, the vacuum in the tube 8 is released and the bulbs are released each above a subsequent burner. The transport device, the suction members of which are now at a small distance freely above the bulbs, is subsequently moved back to point T, which lies above point P. Subsequently, the device drops through the distance TP, and herewith one cycle is performed and a subsequent one may begin.

Transport devices operating in such a manner are known per se. The protective rights claimed here relate solely to their combination with a series of devices for producing smoke. The transport device may be constructed in different ways. It is, for example, also possible to use only the table 4 for supporting the bulbs and to move the bulbs alternately up and down and in the forward direction. Contrary to the example in which the burners are arranged in a straight row, they may alternatively be positioned in the form of a circle.

As an alternative, for producing smoke, use may be made of devices other than burners, for example atomisers, although the invention affords particular advantages in the former case, since it is particularly with burners that the production of smoke is frequently irregular as a result of stoppage.

What I claim is:

l. A method of providing electric lamp bulbs with an inner layer of very small light-diffusing particles comprising the steps of successively placing the bulb in a plurality of spaced positions and burning a compound producing smoke of such particles in an oxygen atmosphere in each position so that the layer formed in each bulb is step-wise built up by the amount of particles deposited on the bulb in each successive position, the placing of said bulb in each position being accomplished by first evacuating the tube, then using the suction produced to move the bulb to the next position, and finally releasing the vacuum produced.

2. A method of providing electric lamp bulbs with an inner layer of very small light-diffusing particles comprising the steps of successively placing the bulb in a plurality of spaced positions and burning an organic silicon compound in an oxygen atmosphere in each position so that the layer formed in each bulb is step-wise built up by the amount of particles deposited on the bulb in each successive position, the placing of said bulb in each position being accomplished by first evacuating the tube, then using the suction produced to move the bulb to the next position, and finally releasing the vacuum produced.

3. A method of providing electric lamp bulbs with an inner layer of very small light-diffusing particles comprising the steps of successively placing the bulb in a plurality of spaced positions and burning an organic silicon compound in an oxygen atmosphere in each position so that the layer formed in each bulb is stepwise built up by the amount of particles deposited on the bulb in each successive position, the placing of said bulb in each position being accomplished by first evacuating the tube, then using the suction produced to move the bulb to the next position, and finally releasing the vacuum produced.

4. A device for coating electric bulbs with an inner layer of very small light-diffusing particles comprising a plurality of burners producing smoke of such particles, each burner being spaced a fixed distance from each other, an evacuator connected to each of said burners, a table above said burners having a series of apertures therein, each aperture being positioned above each burner, and a transport member above said table, said transport member having a number of arms carrying Suction'members, each of said suction members being adapted to engage a bulb when said evacuator exhausts the bulbs whereby the transport member moves the bulbs from one aperture of said table to the next successive aperture whereby the'smoke-from teach burnerzproduces axtplurality of light diffusing .particles which" ,are deposited in superposed layers .on the'inner surface .of said bulbs thereby making coatings .for said bulbs'twhich are substantially uniform.

5. :A device :forcoating electric TblllbS with an .inner layer'of very small light diffusing lparticlescomprising .a pluralityof members for burning 'anorgan'ic silicon :compound in an .oxygen atmosphere to produce smoke of such particles, 1 each .member zbeingzspaced a fixed distance from each other, a common .manifold *for fall of said burners, an evacuator at the .position .of .each of said members which is adapted .to extend intoeach tbulb, a table :above said :burners having a series of apertures therein, :each aperture being: positioned above each burner, .and a transport'member above said table, Jsaid transport member having a number of arms carrying sue- -tion members, each'of "said "suction membersbeing References ited in the file of this patent UNITED STATES PATENTS Number Name Date 2,046,360 Baleke et .a1. July 7,1936 2,160,714 Biggs May 30, 1939 2,164,332 Macksoud July 4, 1939 2,356,136 Wampler Aug. 22, 1944 2,545,896 :Pipkin Mar. 20, 1951 

1. A METHOD OF PROVIDING ELECTRIC LAMP BULBS WITH AN INNER LAYER OF VERY SMALL LIGHT-DIFFUSING PARTICLES COMPRISING THE STEPS OF SUCCESSIVELY PLACING THE BULB IN A PLURALITY OF SPACED POSITIONS AND BURNING A COMPOUND PRODUCING SMOKE OF SUCH PARTICLES IN AN OXYGEN ATMOSPHERE IN EACH POSITION SO THAT THE LAYER FORMED IN EACH BULB IS STEP-WISE BUILT UP BY THE AMOUNT OF PARTICLES DEPOSITED ON THE BULB IN EACH SUCCESSIVE POSITION, THE PLACING OF SAID BULB IN EACH POSITION BEING ACCOMPLISHED BY FIRST EVACUATING THE TUBE, THEN USING THE SUCTION PRODUCED TO MOVE THE BULB TO THE NEXT POSITION AND FINALLY RELEASING THE VACUUM PRODUCED. 